Train information displaying system and method

The invention provides a train information displaying system and method. The train information displaying system comprises a central processing unit, a control operation display screen, a positioning unit, an antenna, an MVB (Multifunction Vehicle Bus) unit, a main switch, a branch switch, a carriage branch processing unit, a train internal displayer and a train external displayer, wherein the positioning unit, the MVB unit, the control operation display screen and the main switch are respectively connected with the central processing unit; the branch switch is connected with the main switch through Ethernet; the train internal displayer and the train external displayer are respectively connected with the branch switch through the carriage branch processing unit; and the antenna is connected with the positioning unit. When data of the positioning unit are lost, a mileage redundancy positioning algorithm is started through the central processing unit, train operating data are provided through the MVB unit and